[bigkahunaranch]

Hey folks, took the plunge a couple years back into full time woodworking.
Mainly focusing on cabinets, built ins, mantles, closet organizers, etc.

In my shop I have four router tables.
One is a cast iron model with a PC 3.5hp router that's 220v. It's my work horse.
I have a horizontal table that I use to make moldings and such.
Then I have two shop built tables that each sport a Milwaukee router.

Since I do a ton of dados, and plywood is notorious for being a variety of thicknesses.
I'm thinking of changing one of the fences to a single point fence with micro adjuster.

Now I'm pretty sure a single point fence would work with edge treatments.
But how would it perform doing dados ???????????

Since I'm terrible at geometry, I'm hoping someone on here can provide me guidance.

Thank you.

 

[Herb Stoops]

The Exact Width Dado Jig takes care of any differing widths in material thickness.

https://www.routerforums.com/jigs-fixtures/127921-building-exact-width-dado-jig-choices.html

Herb

 

[Nickp]

Are you concerned that the fence would not be stable enough for routing a dado in a very wide piece some distance from the fence...? Or other concerns...?

Just trying to understand your question...and how it relates to varying thicknesses of ply...

 

[Cherryville Chuck]

I'm afraid I don't see how the single point is going to help. Your problem is that the router bit is the wrong diameter for the plywood. There are several similar designs of the exact width jig Herb linked to and what is recommended is that you take a piece of the plywood and use it to set the width of the jig. That way you are guaranteed to get the fit right. If you need repeatability from panel to panel then add an arm to the jig that registers against the end of the panels and that way the grooves will all be at the same distance from the ends.

 

[bigkahunaranch]

Are you concerned that the fence would not be stable enough for routing a dado in a very wide piece some distance from the fence...? Or other concerns...?

Just trying to understand your question...and how it relates to varying thicknesses of ply...

I have a good set of undersized bits designed for cutting dados in plywood.
But quite often I will be cutting the dado for 3/4 plywood, I get a good fit, but
then when I come across a piece of plywood that's just 1/32 thicker and won't fit.
Trying to adjust a two point fence 1/32 is not always accurate.
Hence the need of a micro adjuster.

 

[Cherryville Chuck]

Finish plywood starts out the right size but then it gets sanded smooth which is why the various sizes. Sometimes it's easier to trim the end of the ply where it will be going into the groove (or mortise) than the other way around.

A micro adjuster isn't a hard concept to build. All the system is is a screw or bolt that clamps separately to the table so that you can unlock the fence clamps once the adjuster is clamped and turn it and then reclamp the fence. Normally what I do is to put a pencil mark on the table against one end of the fence. Then I unclamp that side (and loosen off a bit on the other side if necessary) and either move towards or away from that mark as needed. Moving only one side is half that adjustment in the center at the bit. That's usually somewhere between a 64th or 32nd which is a pretty fine adjustment in my world.

 

[kp91]

use a 5/8 or 1/2 inch dado bit to plow your dados in the sides of your cabinet. Then use a regular straight bit to put a rabbet on the edges of the shelves to fit it.

 

[MEBCWD]

I think the single point router fence will be a big problem because of small deviations from being 90 degrees form the point will not give you a straight cut.

Just make a simple micro adjuster for your straight fence. Something like this https://www.woodsmith.com/article/router-table-fence-micro-adjuster/

 

[Cherryville Chuck]

I think the single point router fence will be a big problem because of small deviations from being 90 degrees form the point will not give you a straight cut.

Just make a simple micro adjuster for your straight fence. Something like this https://www.woodsmith.com/article/router-table-fence-micro-adjuster/

Nice simple adjuster jig there Mike. The drawing shows using a 5/16" x 18 tpi threaded rod but I highly recommend when using threaded rod to either use 3/8" x 16 tpi or if you're working in metric to use one of the diameters that comes in 1 thread per millimeter. With 3/8" x 16 each full turn is 1/16" and with the metric rod it's 1 mm per turn which makes it easy to calculate how much adjustment you're making.